The inclusion criteria were: both genders, aged 18 to 60, diagnosis of PTSD DSM-IV criteria by a trained psychiatrist after the application of the SCID-I. Women must be using contraceptive methods during the study. Women had to be using contraceptive methods during the study. The exclusion criteria were to have a diagnostic of the following conditions: schizophrenic disorder, delusional disorder, bipolar disorder, psychotic depression episode and psychoactive substance dependency disorder in the previous 6-month period, instable medical diseases, and pregnancy.